I just can't believe the claims in that greentext. 95% of <90 IQ cannot understand "if you had not eaten all day yesterday, how would you feel in the evening?". That's 25% of the population. It's over 50% of certain large demographic subdivisions.

At some point, I'd like to consider whether there's value in developing a protocol + software + device for facilitating personalized randomly controlled trials beyond whatever is the Pareto frontier for current enthusiasts

Wow, yes. I've thought about this before and it feels like this would be so valuable. It's been a while since I've looked into this space but as far as I've been able to tell the Pareto frontier is terrible.

I'm going to try to spend some time on this over the next few days.

I think the changes would be huge and happen right away. At first a lot of people might not know exactly what to do, but some would. As Oscar_Cunningham predicts, I think the financial effects would be the first extreme change. The stock markets would crash, and bank runs and people abusing their credit or withholding loan/ccard payments would cause banks to go under immediately. This would all be in the news the very next day, causing big reactions from everyone.

I'm not sure what the world would look like a few weeks/months after that, but I think it would be pretty extreme. So many sectors (or big parts of them) won't make sense anymore (research, education, construction, policy-making, are a few that come to mind). Many people would try to quit their jobs, even though it would be hard to predict what their savings would turn out to be worth.

I would probably start thinking really hard about how to profit/protect myself, reading online everything I could find about what the most informed people are saying, trying to figure out what I should be doing right away that I wouldn't be able to do later.